Electric motor with a stator formed from a pole chain and with contactless routing of enameled aluminum wire

Abstract

A stator of an electric motor comprises a pole chain, which is made of a stack of a plurality of straight transformer sheets and rounded to a circular configuration by bending the stacked transformer sheets, wherein the pole chain has a plurality of pole portions each comprising a pole tooth; a plurality of winding cores attached to the respective pole teeth for accommodating coils of a three-phase winding comprising wires; wherein the wires of respective phases of the three-phase winding are routed spatially separated from each other and without mutual contact at an axial end surface of the pole chain between and along adjacent winding cores around the pole chain; and wherein the wires are supported and guided such that their positions relative to the pole chain are substantially maintained when the pole chain is rounded from its straight configuration to its circular configuration.

The invention claimed is: 
     
       1. A stator for an electric motor, comprising:
 a pole chain made of a stack of a plurality of straight transformer sheets and rounded to a circular configuration by bending the stacked transformer sheets, 
 wherein the pole chain has a plurality of pole portions each comprising a pole tooth; 
 a plurality of winding cores attached to the respective pole teeth for accommodating coils of a three-phase winding comprising wires; 
 the wires of respective phases of the three-phase winding are routed spatially separated from each other and without mutual contact at an axial end surface of the pole chain between and along adjacent winding cores around the pole chain; 
 wherein the wires are supported and guided such that their positions relative to the pole chain are substantially maintained when the pole chain is rounded from its straight configuration to its circular configuration; 
 wherein a lateral side wall of a coil space of each of the winding cores facing in a circumferential direction of the stator has an inclination angle (γ) larger than an inclination angle (α) of a narrow side of the coil space facing in an axial direction of the stator. 
 
     
     
       2. The stator according to  claim 1 ,
 wherein each of the winding cores further comprises a winding displacement means located at an inner side wall of the coil space of the winding core. 
 
     
     
       3. The stator according to  claim 1 ,
 wherein each winding core further comprises support pins which are configured to support and guide wires from one winding core to adjacent winding cores along spatially separated routing paths. 
 
     
     
       4. The stator according to  claim 3 ,
 wherein the support pins are configured to support and guide wires from one winding core to adjacent winding cores in axially separated routing planes. 
 
     
     
       5. The stator according to  claim 3 ,
 wherein the support pins comprise shoulders or recesses to support the wires and prevent axial movement of the wires. 
 
     
     
       6. The stator according to any of  claim 3 ,
 wherein the support pins have a fork configuration to separately support the wires and prevent axial movement of the wires. 
 
     
     
       7. The stator according to any of  claim 3 ,
 wherein the support pins are located such that the wires are guided from winding core to an adjacent winding core along a path which passes nearby or intersects with a pivot axis about which adjacent pole teeth are pivoted when the pole chain is rounded to its circular configuration. 
 
     
     
       8. The stator according to  claim 1 ,
 wherein the wires are enameled wires made from aluminum or aluminum alloy. 
 
     
     
       9. The stator according to  claim 1 ,
 wherein the wires are routed in three axially separated routing planes having different axial levels along the axis of the rounded pole chain, wherein each wire is routed between the coils in a respective one of the planes. 
 
     
     
       10. The stator according to  claim 9 ,
 wherein each winding core further comprises support means configured to support and guide the respective wire to a respective one of the separated routing planes when entering or exiting the coil on the winding core. 
 
     
     
       11. The stator according to  claim 9 ,
 wherein each winding core further comprises support divider means which are formed as a recess in a coil space boundary wall of the winding core, the recess having a depth which is set so that a bottom line of the recess is located at the axial level of one of the routing planes. 
 
     
     
       12. The stator according to  claim 11 ,
 wherein at least one support divider means further comprises a winding gradation means.